A geared motor includes a motor and a gear mechanism for transmitting rotation of the motor. In the gear mechanism, a structure in which a protruded part comprised of a teeth non-formation part is provided in one of the gears and a recessed part comprised of a tooth-missing part is provided in the other of the gears has been proposed as a structure for matching the phase of the gears with each other (see, Japanese Patent Laid-Open No. 2009-2422).
According to this structure, the phase of the gears can be matched with each other with the protruded part provided in one of the gears and the recessed part provided in the other of the gears as a reference.
However, in the structure described in Patent Literature 1, the phase of the gears directly engaged with each other can be matched but it is difficult that the phase between gears which are connected with each other through other gears is matched. Further, when a protruded part and a recessed part formed of a teeth non-formation part are utilized, in a gear whose teeth number is small, the meshing ratio is lowered and thus turning of the gear may be performed unsatisfactory.